Women have been bleaching their hair for thousands of years. Some of the primitive concoctions used to bleach hair in early Rome, prior to the beginning of the Christian era, included native minerals such as alum, soda, and wood ash combined with wine dregs or water. Such preparations were often left on the hair for several days, and lightened very dark hair to a desirable reddish gold in color. A number of books published during the Renaissance also disclose various formulas for bleaching hair. Typically these compositions were based upon ingredients such as alum, borax, or soda, in combination with plant extracts. It has also been reported that Venetian women obtained their blond hair by sponging it with a solution of soda (or rock alum, black sulfur, and honey) through the hair, spread it over the broad brim of a crownless hat, and let it dry in the sunlight [Cosmetics: Science and Technology, Second Edition, Volume 2, 1972]. This treatment persisted for hundreds of years thereafter, until the fashions changed.
Modern hair bleaches are much milder and non-toxic when compared to their historical counterparts. The key ingredient is a mild oxidizing agent, which is most often hydrogen peroxide. Hydrogen peroxide exerts both a chemical and physical effect on the hair. It is capable of penetrating the hair cuticle and oxidizing the melanin (which provides color) so that the hair becomes noticeably lighter. If treated for a long enough period of time, hair can be colored to very light blonde or white, although it has been said that hair bleached with hydrogen peroxide only may tend to exhibit a yellowish tinge.
Currently, hair bleaches are most commonly found in the two or three component kit form. One component comprises an aqueous based hydrogen peroxide containing solution or emulsion. The second component comprises a powdered bleach composition that contains persulfate salts which act as accelerators of the bleaching process when the two components are combined. The third component, if present, is an alkalizing composition, or a composition that provides alkaline properties. The hydrogen peroxide, persulfates, and, if present, the alkalizing composition, are very reactive when combined, and form nascent oxygen in addition to hydrogen and sodium sulfide. The nascent oxygen greatly facilitates oxidizing and bleaching of melanin from the hair. Typical bleaches generally have a pH of 9 to 11 and are applied to hair for 30 to 60 minutes to achieve the desired results.
Hair bleaches may be used to treat the entire head of hair or only select strands. Highlighting involves application of the bleach composition to only select strands of hair to provide a dappled color effect to the hair. Highlighting is a very popular procedure in both salons and at home. A wide variety of retail highlighting kits are available for purchase by the at home user. Hair products companies make every effort to design the retail kits in the most consumer friendly manner possible to ensure that the at home user has the highest probability of success in obtaining professional quality highlights. The applicator used to the apply the bleach mixture is important in this regard, as is the actual formula for the aqueous oxidizing agent composition, the persulfate composition, and, optionally the bleach oil composition, that are combined to form the bleach mixture.
One common problem with such bleach mixtures is that once they are applied in streaks to the hair, the mixture migrates or diffuses into the surrounding hair shafts. In some cases the streaks initially applied to hair may diffuse so much that they may form one large patch of product on the hair. These large patches result in patches, rather than defined streaks, of highlighted hair and provide a very unprofessional end result. Companies that make and sell hair bleach products are interested in formulating bleach products that exhibit reduced migration or diffusion on the hair, with the end result being more professional looking highlights.
It is an object of the invention to provide a bleach mixture for bleaching or highlighting hair that exhibits reduced migration and diffusion upon application to the hair.
It is a further object of the invention to provide a bleach mixture that provides more professional looking highlights to hair.
It is a further object of the invention to provide a bleach mixture that provides hydrophobically modified particulates in an amount sufficient to cause the mixture to exhibit reduced migration and/or diffusion when applied to the hair.
It is a further object of the invention to provide a method for reducing the diffusion and/or migration of a bleach mixture after it is applied to hair by including one or more hydrophobically modified particulates in the bleach mixture.
It is a further object of the invention to provide a method for improved highlighting of the hair comprising applying to the hair a bleach mixture containing hydrophobically modified particulates that cause reduced migration or diffusion of the bleach composition when it is applied to the hair.
It is a further object of the invention to provide a persulfate bleach composition comprising at least one hydrophobically modified silica.
It is a further object of the invention to provide a kit for bleaching or highlighting hair comprising (a) an aqueous oxidizing agent composition, (b) a persulfate bleach composition containing at least one hydrophobically modified particulate; and, optionally, (c) a bleach oil composition.